If you die then your BTC will be secure in your wallet. But if you tell your private keys and password to anyone then he will access you wallet otherwise your BTC will Secured in your wallet for life time.
It's true that bitcoins will still be stored neatly in our private wallets, if no one knows our wallet's private keys. If anyone knows about our private key, of course he (who knows the private key) will take ownership.
But I think, we have prepared for it, as for example we will give to our heirs.